package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    //序列号的位数
    public static final int COUNT_BITS = 32;
    //开始时间戳
    public static final long BEGIN_TIMESTAMP = 1640995200L;
    @Resource
    StringRedisTemplate stringRedisTemplate;

    public long nextId(String keyPrefix){
        //1、生成时间戳
        long nowsecond = LocalDateTime.now().toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowsecond - BEGIN_TIMESTAMP;
        //2、生成序列号
        //2.1 获取当前日期，精确到天
        String date = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //2.2 自增长
        long count = stringRedisTemplate.opsForValue().increment("icr" + keyPrefix + ":" + date);
        //3、拼接并返回
        return timestamp << COUNT_BITS | count;
    }

}
